Process for producing liquid crystal display device and liquid crystal display device

ABSTRACT

A process for producing a liquid crystal display device enabling to produce with simple process, and such a liquid crystal display device, are provided. 
     A process for producing a liquid crystal display device comprising: a step of forming transparent electrodes ( 41, 42 ) on first and second substrates ( 11, 12 ); a step of applying an uncured raw seal material; a step of dropping a first functional material; a step of dropping a second functional material; a step of sandwiching the raw seal material ( 13   a,    14   a ), the first functional material ( 32   a ) and the second functional material ( 31   a ) between the first and second substrates under a predetermined reduced pressure atmosphere, and thereby forming a sealed product wherein the first functional material is isolated from the second functional material by the raw seal material and sealed between the first and the second substrates; a step of exposing the sealed product to a normal atmospheric pressure; and a step of curing at least the raw seal material.

TECHNICAL FIELD

The present invention relates to a process for producing liquid crystaldisplay device and to a liquid crystal display device, in particular, toa process for producing a liquid crystal display device having alight-control function or a display function only in a partial area on atransparent substrate and to such a liquid crystal display device.

BACKGROUND ART

Heretofore, a technique of sandwiching a liquid crystal panel togetherwith a transparent resin between two glass substrates, to form alight-control window of laminated glass structure, has been proposed(refer to Patent Document 1). By employing this technique, it ispossible to provide light-control function only to a part of the glasssubstrate by embedding a small-sized liquid crystal panel between twoglass substrates.

Patent Document 1: JP-A-2004-131335

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, there is a limit in thickness reduction of liquid crystalpanel, and it has not been easy to reduce the thickness of alight-control window produced by the above technique. Further, since astep of producing a liquid crystal panel and a step of sandwiching thepanel together with a transparent resin between two glass substrates arerequired, there has been a problem that production process iscomplicated. Further, there has also been a problem that it is difficultto lead out wirings from the liquid crystal panel to an edge of a glasssubstrate.

In order to solve these problems, it is an object of the presentinvention to provide a process for producing a liquid crystal displaydevice having more simple structure than those of conventional devices,produceable by simple process and provided with light-control functiononly in a partial area on a substrate; and to provide such a liquidcrystal display device.

Means for Solving the Problem

The present invention provides a process for producing a liquid crystaldisplay device comprising: a step of forming transparent electrodes onfirst and second substrates; a step of applying an uncured raw sealmaterial to at least one of the first and second substrates; a step ofdropping a first functional material containing liquid crystal on atleast one of the first and second substrates; a step of dropping asecond functional material containing no liquid crystal on at least oneof the first and second substrates; a step of sandwiching the raw sealmaterial, the first functional material and the second functionalmaterial between the first and second substrates under a predeterminedreduced pressure atmosphere, and thereby forming a sealed productwherein the first functional material is isolated from the secondfunctional material by the raw seal material and sealed between thefirst and second substrates; a step of exposing the sealed product to anormal atmospheric pressure; and a step of curing at least the raw sealmaterial.

Further, in an embodiment of the process for producing a liquid crystaldisplay device of the present invention, the first functional materialcomprises a composite of liquid crystal and curable compound, or aliquid crystal, and the second functional material comprises atransparent or a colored resin. Further, in an embodiment of the processfor producing a liquid crystal display device according to the presentinvention, the composite and the seal material each has a visible lighttransmittance of at least 70% in a transparent state. Further, in anembodiment of the process for producing a liquid crystal display deviceaccording to the present invention, the raw seal material comprises apolyene-polythiol system polymer. Further, in an embodiment of theprocess for producing a liquid crystal display device according to thepresent invention, the absolute value of the difference between the hazevalue of the seal material and the haze value of the composite in atransparent state, is at most 3%. Further, an embodiment of the processfor producing a liquid crystal display device according to the presentinvention, further comprises a step of cutting the first and the secondsubstrates in a region different from a region wherein the firstfunctional material is sealed. Further, an embodiment of the process forproducing a liquid crystal display device according to the presentinvention, further comprises a step of forming a through hole perforatedthrough the first and second substrates in a region different from aregion wherein the first functional material is sealed.

Further, the present invention provides a liquid crystal display devicecomprising first and second substrates that are disposed so as to opposeto each other and each having a transparent electrode; a first sealmaterial for forming a first space between these substrates; a secondseal material for forming a second space between the first and secondsubstrates; a first functional layer provided in the first space; and asecond functional layer provided in the second space; wherein the firstfunctional layer comprises a composite layer containing liquid crystaland cured product, and the composite and the seal material each has avisible light transmittance of at least 70% in a transparent state. Inan embodiment of the liquid crystal display device according to thepresent invention, the seal material comprises a polyene-polythiolsystem polymer. In an embodiment of the liquid crystal display deviceaccording to the present invention, the absolute value of the differencebetween the haze value of the seal material and the haze value of thecomposite in a transparent state is at most 3%.

Effect of the Invention

The liquid crystal display device according to the present invention hasa thinner design than conventional devices, wherein a first functionallayer such as a liquid crystal layer and a second functional layer suchas a transparent resin layer are sandwiched between two substrates in astate of mutual detachment by a seal material so as not to overlap eachother. Further, the process for producing the liquid crystal displaydevice according to the present invention can be achieved with simpleprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1( a) and 1(b): plan views showing an embodiment of the presentinvention.

FIG. 2: a cross-sectional view schematically showing a cross-sectionalong a II-IP line.

FIGS. 3( a) to 3(c): a plan view showing another embodiment of thepresent invention.

FIG. 3( d): a cross-sectional view along a III-III′ line.

FIG. 4: a flow chart showing an embodiment of the production process ofthe present invention.

FIG. 5: a plan view showing an example of a seal material after it isapplied.

FIGS. 6( a) to 6(d): cross-sectional views along a IV-IV′ line, showingan embodiment of the production process of the present invention.

FIG. 7: an explanation view showing an embodiment of the productionequipment of the present invention.

FIG. 8: a plan view showing another embodiment of the present invention.

FIGS. 9( a) and 9(b): plan views showing another embodiment of thepresent invention.

FIGS. 10( a) and 10(c): plan views showing another embodiment of thepresent invention.

FIG. 10( b): a cross-sectional view along a X-X′ line of anotherembodiment of the present invention.

FIG. 11: a plan view showing another embodiment of the presentinvention.

EXPLANATION OF NUMERALS

10, 10 a: Liquid crystal display device

11, 12: Substrate

13, 14: Seal material

13 a: Edge portion

15, 16, 15 a, 16 a: Terminal

17, 18: Wiring

31: Transparent resin layer

32: Composite layer

41, 42: Transparent electrode

43: Spacer

100: Vacuum laminating apparatus

101: Vacuum chamber

102: Electrostatic chuck

103: Surface plate

200: Drive unit

BEST MODE FOR CARRYING OUT THE INVENTION

Next, embodiments of the present invention will be described. However,the present invention is not limited to the following embodiments.Further, every drawing is shown schematically, and may include asimplified part or differently-scaled part from a real thing.

FIGS. 1( a) and 1(b) are plan views showing an embodiment of the presentinvention. FIG. 2 is a cross-sectional view schematically showing across-section along a II-II′ line of FIG. 1( a). The liquid crystaldisplay device 10 has a first transparent substrate 11, a firsttransparent electrode 41, a second transparent substrate 12, a secondtransparent electrode 42, a first seal material 13, a second sealmaterial 14, spacers 43, a transparent resin layer 31 and a compositelayer 32.

As shown in FIG. 2, on opposing surfaces of the transparent substrates11 and 12, transparent electrodes 41 and 42 are formed so as to coverentire respective surfaces. In four corners of the transparentsubstrates, the transparent substrates are partially cut off so that thetransparent electrodes 41 and 42 are exposed to configure terminals 15and 16 respectively. The terminals 15 and 16 are connected to a powersupply circuit 20 via wirings 17 and 18 respectively.

Here, transparent electrodes 41 and 42 may be provided on a part of thetransparent substrates 11 and 12.

Further, the transparent resin layer 31 and the composite layer 32comprising a composite of liquid crystal and cured product, aresandwiched between the first transparent substrate 11 and the secondtransparent substrate 12. The first seal material 13 has a ring shapewhen the liquid crystal display device 10 is observed from the frontside, and the inside of the ring is filled with the composite layer 32without gap. A partitioned region between the first seal material 13 andthe second seal material 14 is filled with the transparent resin layer31 without gap. Accordingly, only a region 13 b surrounded by the firstseal material 13 has a display function (transparentstate/non-transparent state is switched depending on application ofvoltage) by a liquid crystal, and other regions remain transparent atany time irrespective of voltage application. The seal materials 13, 14are preferably made of a transparent resin from the viewpoint of design,but they may be made of a colored resin depending on their application.Similarly, the transparent resin layer 31 may be made of the samematerial as the seal materials 13, 14.

The first and second transparent substrates 11 and 12 are electricallyinsulating transparent substrates, and they may, for example, be glasssubstrates, resin substrates such as polycarbonate or acrylic, or resinfilms. The first transparent substrate 11 shown in FIGS. 1( a) and 1(b)has substantially the same size as the second transparent substrate 12,but they may be different from each other. Further, between the firsttransparent substrate 11 and the second transparent substrate 12, aplurality of regions each surrounded by a ring-shaped seal material maybe provided.

The first and second transparent electrodes 41 and 42 may, for example,be made of ITO (indium tin oxide). The shape of a region 13 b surroundedby the first seal material 13 when the liquid crystal display device 10is observed from the front side, is not limited to a rectangle, but itmay be a circle, a triangle or a shape such as specific mark, characteror letter.

Further, on each of the first and second transparent electrodes 41 and42, an alignment film (not shown) is formed. The alignment film contactswith the composite layer 32 so as to align liquid crystal moleculescontained in the composite layer 32 in a predetermined direction.Further, between the transparent electrode and the alignment film, aninsulating thin film such as metal oxide may be provided to improveelectrical insulation properties. Meanwhile, a configuration withoutalignment film may be acceptable depending on the type of the liquidcrystal or the composite layer.

The first seal material 13, the second seal material 14 and thetransparent resin layer 31 are made of, for instance, UV-curable resin(hereinafter referred to as UV resin) or a thermosetting resin. Spacers43 are uniformly distributed in a space enclosed by the first and secondsubstrates 11 and 12 and the first seal material 13. Though the spacers43 are employed to control a cell gap in the composite layer 32, thespacers 43 may be distributed in the transparent resin layer 31. Thecell gap, that is the diameter of each spacer 43, is preferably from 2to 50 μm, more preferably from 4 to 30 μm. If the cell gap is too small,contrast of display decreases, and if the cell gap is too large, drivingvoltage increases. The spacers 43 are made of a hard material such asglass particles, silica particles or crosslinked acrylic particles.Meanwhile, instead of spherical spacers, rib-shaped or fiber-shapedspacers may be formed on one of the substrates.

Further, the seal material being transparent after curing may, forexample, be a polymer of epoxy system, acrylic system, urethane systemor polyene-polythiol system, or a mixed system of these. Thermosettingtype or photocurable type material is employed for the seal material.Particularly, a polyene-polythiol system polymer is preferred, and itcan achieve a visible light transmittance of at least 70%. Further, bydropping a raw material for transparent resin comprising apolyene-polythiol system polymer in a region surrounded by the sealmaterials 13 and 14, it is possible to make the visible lighttransmittance of the transparent resin layer to be 70%.

Here, the visible light transmittance in this explanation is measured bySPECTRO MULTI CHANNEL PHOTO DETECTOR (MCPD-10000) manufactured by OtsukaElectronics Co., Ltd. Further, the haze value is measured by direct-readhaze computer HGM-2, manufactured by Suga Test Instruments Co., Ltd.

A specific example of the seal material is as follows.Tris-2-hydroxyethyl isocyanurate-tris-3-mercapto propionate (molecularweight: 526) and triallyl isocyanurate (molecular weight: 250) are mixedat a ratio of [tris-2-hydroxyethyl isocyanurate-tris-3-mercaptopropionate:triallyl isocyanurate=2.1:1 (mass ratio)]. Further, 1 wt % ofphotopolymerization initiator (benzoine isopropyl ether) for the totalamount of the above two monomers is added. They are stirred well, and0.3 wt % of glass spacers (gap diameter: 6 μm) are added against thetotal weight, they are further stirred to form a seal material in whichthe glass spacers are uniformly distributed, and the seal materialobtained may be used as the seal material 13 and 14.

Meanwhile, a seal material having a visible light transmittance of lessthan 70% may be as follows.

To World lock No. 717 (epoxy resin compound manufactured by KyoritsuChemical & Co., Ltd.), 0.3 wt % of glass spacers (gap diameter: 6 μm)are added, they are stirred to form a material in which glass spacersare uniformly distributed, and it may be used as the seal material 13and 14.

Further, to Stretbond S-45 (manufactured by Mitsui Chemicals, Inc.), 0.3wt % of glass spacers (gap diameter: 6 μm) are added, they are stirredto form a material in which glass spacers are uniformly formed, and itmay be used as the seal material 13 and 14.

The composite layer 32 is sealed in a space enclosed by the first andsecond transparent substrates 11 and 12 and the seal material 13. Thecomposite layer 32 comprises a mixture of liquid crystal and curedproduct. Specific components will be described later. Since the liquidcrystal is vertically aligned and has a domain structure, the incidentlight into the composite layer 32 is scattered at a time of voltageapplication. Accordingly, hereinafter, the region in which the compositelayer 32 is formed when the liquid crystal display device 10 is observedfrom the front side is referred to as a scattering display area. Thescattering display area is in transparent state at a time of no voltageapplication, and the transmittance changes with the voltage applicationto be scattering state.

The liquid crystal employed in the composite layer 32 may, for example,be a nematic liquid crystal that is a material of electric field drivetype. It may be a combination of two or more kinds of liquid crystals.Further, for the purpose of an electric-field control display, a liquidcrystal having a negative dielectric anisotropy is preferably employedsince the transmittance in a transparent state can be increased byvertically aligning the liquid crystal, but positive/negative of adielectric anisotropy can be appropriately selected. Further, in orderto reduce the driving voltage, dielectric anisotropy is preferably high.

The composite layer 32 to be employed for the liquid crystal displaydevice 10 according to an embodiment of the present invention, ispreferably a composite layer obtained by polymerizing curing of acomposite material containing at least a curable compound and the saidnon polymerizable liquid crystal, wherein the curable compound containsone or more kinds of bifunctional polymerizable compound (A) representedby the following formula (1) and one or more kinds of bifunctionalpolymerizable compound (B) represented by the following formula (2).When the composite layer 32 has such a composition, the visible lighttransmittance of the composite layer 32 can be at least 70%. Further, bycomprising the seal material by a polyene-polythiol system polymer, itis possible to make the absolute value of the difference between thehaze value of the seal material and the haze value of the compositelayer in the transparent state, to be at most 3%.

A¹-R¹—X¹-(Q³Z²)_(p)-Q¹-Z¹-Q²-(Z³-Q⁴)_(q)X²-R²A²   (1)

A³-R³-A⁴   (2)

Bifunctional polymerizable compound (A) is a component for forming arigid backbone in the composite. Meanwhile, the bifunctionalpolymerizable compound (B) is a component for forming a flexible portionwhich can play a role of shock absorption in the composite. By combiningsuch compounds having different physical properties, a composite layer32 of liquid crystal and cured product suitable for the liquid crystaldisplay device 10 of the present invention is obtained. Of course thecurable compound (polymerizable compound) for forming cured product isnot limited thereto.

The bifunctional polymerizable compound (A) is a compound having amesogenic structure, and among compounds represented by the formula (1),ones having the following first to third embodiments are preferred. Anembodiment for carrying out the present invention is preferably thefirst embodiment, more preferably the second embodiment than the firstembodiment, still more preferably the third embodiment than the secondembodiment.

First Embodiment of Bifunctional Polymerizable Compound (A)

In the first embodiment, symbols in formula (1) have the followingmeanings.

A¹, A² are each independently an acryloyloxy group, a methacryloyloxygroup or a vinyl ether group.

Q¹, Q², Q³ and Q⁴ are each independently a 1,4-phenylene group or a1,4-cyclohexylene group that may have a substituent group.

X¹ and X² are each independently a single bond, an oxygen atom or anester bond.

R¹ and R² are each independently a single bond or a linear or branchedalkylene group containing 2 to 20 carbon atoms that may have one or aplurality of ethereal oxygen atoms between carbon atoms.

Z¹, Z² and Z³ are each independently a single bond, —C(═O)—O—,—O—C(═O)—, —CH₂—CH₂—,

—C≡C—, —CH₂—O— or O—CH₂—.

p and q are both 0 or one of them is 0 and the other is 1.

Second Embodiment of Bifunctional Polymerizable Compound (A)

In the second embodiment, symbols in formula (1) have the followingmeanings.

A¹ and A² are each independently an acryloyloxy group or amethacryloyloxy group.

Q¹ and Q² are each 1,4-phenylene group that may have a substituentgroup, and Q³ and Q⁴ are each independently a 1,4-phenylene group or a1,4-cyclohexylene group that may have a substituent group.

X¹, X², R¹ and R² have the same meanings as those described above.

Z¹, Z² and Z³ are each independently a single bond, —C(O)—O—, —O—C(═O)—,—CH₂—CH₂— or C≡C—.

p and q are both 0 or one of them is 0 and the other is 1.

Third Embodiment of Bifunctional Polymerizable Compound (A)

In the third embodiment, symbols in formula (1) have the followingmeanings.

-   -   A¹ and A² are both acryloyloxy groups.

Q¹ and Q² are both 1,4-phenylene groups that may have a substituentgroup, and Q³ and Q⁴ are each independently a 1,4-phenylene group or a1,4-cyclohexylene group that may have a substituent group.

X¹ and X² have the same meanings as those described above.

R¹ and R² are each independently a linear or branched alkylene groupcontaining from 2 to 20 carbon atoms.

Z¹ is a single bond, —C(═O)—O—, —O—C(═O)—, —CH₂—CH₂— or C≡C—, and Z² andZ³ are each a single bond.

p and q are both 0 or one of them is 0 and the other is 1.

A specific example of the bifunctional polymerizable compound (A) may bea compound of the following formula (3).

The bifunctional polymerizable compound (A) may be a liquid crystallinecompound, or it may be a non-liquid crystalline compound. Thebifunctional polymerizable compound (A) may be only a non-liquidcrystalline bifunctional polymerizable compound (A), only a liquidcrystalline bifunctional polymerizable compound (A), or a combination ofthe non-liquid crystalline bifunctional polymerizable compound (A) andthe liquid crystalline bifunctional polymerizable compound (A).

The bifunctional polymerizable compound (B) is a compound having nomesogenic structure, and is preferably a compound represented by thefollowing formula (2).

A³-R³-A⁴   (2)

A³ and A⁴ are each independently an acryloyloxy group, a methacryloyloxygroup or a vinyl ether group.

R³ is —R⁴— or —(R⁵—O)_(n)—R⁵—.

Note that R⁴ and R⁵ have the meaning of following (i) or (ii),preferably (i), more preferably (ii).

(i) R⁴ is a linear or branched alkylene group containing from 2 to 20carbon atoms, R⁵ is a linear or branched alkylene group containing from2 to 8 carbon atoms, and n is an integer chosen from 1 to 10.

(ii) R⁴ is a linear alkylene group containing from 2 to 20 carbon atoms,and R⁵ is —(CH₂)_(r)—,

—CH₂—CH(CH₃)—, —CH₂—CH₂—CH(CH₃)— or —CH₂—CH₂—C(CH₃)₂— wherein r is aninteger chosen from 2 to 5, and n is an integer chosen from 1 to 10. Thebifunctional polymerizable compound (B) may be used alone, or two ormore kinds of such compounds may be used in combination. Thebifunctional polymerizable compound (B) may, for example, be a compoundrepresented by the following formula (4).

The bifunctional polymerizable compound (B) has polymerizable groups A³and A⁴ and a divalent group R³ connecting the said polymerizable groupsA³ and A⁴. It is preferably for R³ to select a group having a moietywhere atoms constituting R³ are connected by a single bond with eachother and thus having high degree of the rotational freedom in themolecule. By such a configuration, it is possible to improve flexibilityof cured product obtained through curing reaction. Further, it ispossible to make polymerization phase separation progress smoothly.

As the number of carbon atoms and ethereal oxygen atoms of the group R3present between A³ and A⁴ increases, flexibility of the cured productobtained after curing improves. On the other hand, as the number ofthese atoms increases, compatibility with liquid crystal at a time ofpreparing the composite material decreases. Further, in a case ofemploying an ODF (one drop fill) method, considering volatility, thenumber of carbon atoms of the bifunctional polymerizable compound (B) isat least 8, preferably at least 11. It is preferred to select thestructure (number of atoms and type of constituent atoms) of the groupR3 with all things considered.

The group R³ may contain ethereal oxygen atom(s) or it may contain nosuch oxygen atom. When R³ contains ethereal oxygen atom(s), flexibilityof the cured product improves, such being preferred.

Since the bifunctional polymerizable compound (B) contains no group(cyclic group) such as Q1 in the molecule, it is relatively easy toincrease the number of carbon atoms contained in R3 withoutsignificantly increasing the number of carbon atoms contained in theentire compound. By employing this structure, it is possible tosignificantly improve flexibility of a composite layer obtained bycuring the curable compound from a composite material, whilecompatibility with liquid crystal is maintained. In the presentinvention, the composite material may contain a polymerization initiatorfor initializing curing of a curable compound or a curing promoter (suchas curing catalyst) for promoting curing. Particularly, thepolymerization initiator is preferably employed. Such a polymerizationinitiator may be appropriately selected from known polymerizationcatalysts. For example, in a case of employing a photopolymerizationphase separation method, a common photopolymerization initiator of suchas benzoin ether system, acetophenone system or phosphine oxide system,may be employed.

Further, in order to improve contrast ratio or stability, variouscompounds may be added to the composite material. For example, in orderto improve contrast, various kinds of dichroic dyes such as those ofanthraquinone system, styryl system, azomethine system or azo system maybe employed. In this case, the dichroic dye is basically preferablysoluble to the liquid crystal compound, and preferably insoluble to thecurable compound. Besides these, an antioxidant, a UV-absorbing agent orvarious kinds of plasticizers are preferably added for the purpose ofimproving stability or durability.

Next, operation of the above-described liquid crystal display device 10will be described.

When a voltage is applied between the first and second transparentelectrodes 41 and 42, liquid crystal molecules are randomly oriented byelectric field between the electrodes, whereby the composite layer 32becomes a scattering state. On the other hand, when no voltage isapplied between the first and second transparent electrodes 41 and 42,the liquid crystal molecules are aligned, whereby the composite layer 32becomes a transparent state. The composite layer 32 in the transparentstate enables an observer to observe a view through a back side (asurface on the other side from the position of observer) of the liquidcrystal display device 10.

Meanwhile, the liquid crystal display device may be one being in atransparent state at a time of voltage application and a scatteringstate at a time of non-voltage application. However, in a case ofautomobile use, from the viewpoint of fail safe, the device ispreferably one being in a scattering state at a time of voltageapplication and a transparent state at a time of non-voltageapplication.

Next, FIGS. 3( a) to 3(d) show another embodiment of the presentinvention. As shown in FIG. 3( a), a liquid crystal display device 10 isproduced in the same manner as FIG. 1( a), and the device is cut by adicer along a broken line in the Figure to produce a structure shown inFIG. 3( b). Subsequently, a part of four corners of the substrates arecut off to form terminals 15 a and 16 b, to thereby produce asmall-sized liquid crystal display device 10 a shown in FIG. 3( c). Inthis embodiment, the seal material 13 is preferably made of atransparent resin, but the seal material 14 may be made of commonly usedcolored resin since it is removed in a subsequent step. The transparentresin layer 31 may be made of a colored resin according to applicationof the device. In each side of the rectangular liquid crystal displaydevice 10 a, the transparent resin layer 31 is exposed (FIG. 3( d)).

Next, a process for producing the liquid crystal display device 10 ofthe present invention will be described.

FIG. 4 is a flow chart showing an embodiment of the production processof the present invention. FIG. 5 is a plan view showing an embodiment ofa seal material after it is applied. FIG. 6 is a cross-sectional viewshowing an embodiment of the production process of the presentinvention. FIG. 7 is an explanation view showing an embodiment of aproduction apparatus of the present invention.

First, on one surface of each of the first and second transparentsubstrates 11 and 12, a transparent electrode film for forming a firstor second transparent electrodes 41 or 42, is formed by such as asputtering method or a vacuum evaporation method (step S1). Thetransparent electrode film is preferably ITO. Thereafter, thetransparent electrode film may be patterned by a photolithography methodand by etching, but in this embodiment, these methods are not used andas shown in FIG. 2, a so-called full-surface electrode formed to coverentire region of one surface of each substrate, is employed.

Next, on each of surfaces of the first and second transparent substrates11 and 12 on which a transparent electrode is formed, an alignment film(not shown) is formed (step S2). The alignment film is formed so that itcontacts with the composite layer 32 so as to align liquid crystalmolecules contained in the composite layer in a predetermined direction.As described above, among alignment films formed on the transparentsubstrates 11 and 12, at least one alignment film is formed so as toalign liquid crystal molecules vertically against the surfaces of thetransparent substrates 11 and 12. Meanwhile, the alignment film on thetransparent substrate 11 may be formed only in a region facing to thetransparent substrate 12. Further, between the transparent electrode andthe alignment film, an insulating film of such as metal oxide may beprovided for the purpose of improving electrical insulation properties.

Next, on the opposed surfaces of the first and second transparentsubstrates 11 and 12, spacers 43 are sprayed by a sprayer (step S3).

Next, on the opposed surfaces of the first transparent substrate 11 andsecond transparent substrate 12, the first raw seal material 13 a andthe second raw seal material 14 a which are uncured are applied (stepS4; FIG. 6( a)). For raw seal materials 13 a and 14 a, such as a UVcurable resin or a thermosetting resin may be employed. Meanwhile, theraw seal materials may be applied at a plurality of locations so as toform a plurality of ring-shaped regions to thereby form a plurality ofkinds of liquid crystal layers and resin layers.

Next, inside a ring-shaped raw seal material 13 a applied on the firstor the second transparent substrate 11 or 12, a composite material 32 abeing a first functional material comprising a mixture of a nematicliquid crystal and an uncured curable compound (photocurable compound),is dropped (step S5). Subsequently, in a region surrounded by the firstraw seal material 13 a and the second raw seal material 14 a, atransparent resin material 31 a being a second functional material isdropped (step S6; FIG. 6( b)). FIG. 5 shows an example of thetransparent substrate 11 on which the transparent resin material 31 aand the composite material 32 a are dropped.

Next, in a vacuum chamber 101 of a vacuum laminating apparatus 100 shownin FIG. 7, the transparent substrates 11 and 12 are placed. Thetransparent substrate 11 is placed on a surface plate 103, and thetransparent substrate 12 is fixed and held by an electrostatic chuck 102that is movable up and down by a drive unit 200. Thereafter, inside thevacuum chamber 101 is evacuated by a vacuum apparatus to make it in apredetermined reduced pressure state, and then, the electrostatic chuck102 is moved down so that the first and second transparent substrates 11and 12 are laminated through the raw seal material 31 a and thecomposite material 32 a (step S7; FIG. 6( c)). Subsequently, air isintroduced into the vacuum chamber 101 so that the transparentsubstrates 11 and 12 etc. are exposed to a normal atmospheric pressure(step S8). By this step, a space enclosed by the first and secondtransparent substrates 11 and 12, the seal material 13 and the sealmaterial 14, becomes substantially a closed space, and a compositematerial or a transparent resin material (optical bonding resin) isinjected into the closed space. For the above steps, so-called ODF (onedrop fill) method is applied.

Next, the raw seal materials 13 a and 14 a, uncured photocurablecompound in the composite material 32 a, and a transparent resinmaterial 31 a, are exposed to be cured with such as a UV light source(step S9; FIG. 6( d)). By the exposure, the photocurable compound iscured and a composite layer of liquid crystal and cured product, isformed. If the raw seal materials 13 a and 14 a and the transparentresin material 31 a are not photocurable compounds, curing of the rawseal materials 13 a and 14 a and the transparent resin material 31 aneeds to be carried out by such as heating separately.

Next, another embodiment of the present invention will be described.

FIG. 8 is a plan view showing another embodiment of the presentinvention. A liquid crystal display device 50 has the same configurationas that shown in FIGS. 1 and 2 except that a region of an electrodesurrounded by a seal material 53 is patterned, and that 4-digit numbersand a colon symbol are each displayed independently. Display control iscarried out by a power supply circuit 56 connected with each electrodepattern. Further, the composite layer is formed only in a partial areasurrounded by the seal material 53, and a transparent resin is sealed ina region surrounded by the seal materials 54 and 53. The periphery ofthe transparent substrates is held with a frame 55 made of a metal suchas aluminum so that the liquid crystal display device 50 is usable as anopening member such as a building window. On one or both surfaces of theliquid crystal display device 50, a reinforcing glass plate may bebonded through an intermediate film made of such as PVB or EVA. Thisglass plate may, for example, be a heat reflecting glass or a temperedglass.

Further, the present invention realizes the following embodiment.

As shown in FIG. 9( a), a liquid crystal display device 60 has the sameconfiguration as that shown in FIG. 1 but differs in that the shape of aseal material 63 for forming a composite layer is circular, and that thedevice has through holes 62 a and 63 d.

In a region surrounded by a seal material 64, a transparent resin issealed and four through holes 62 a are provided. These through holes areopened after the transparent resin is cured. Further, in a regionsurrounded by the seal material 63 and filled with a composite materialsealed, a through hole 63 a is provided. By creating a circular regionsurrounded by a seal material 63 b beforehand, it is possible to preventa composite layer from leaking out even if the through hole 63 a isopened after the transparent substrates are bonded together. Further, ona surface of a transparent substrate 12 (positioning on front side ofthe Figure) configuring the liquid crystal display device 60, characters63 c can be formed by printing or pasting a seal.

As shown in FIG. 9( b), bolts 62 b may be inserted into the throughholes 62 a to fix the liquid crystal display device 60 on such as a wallface. Into a through hole 63 a, a rotational axis for long hand andshort hand of clock is inserted, whereby the liquid crystal displaydevice can be used as a clock having an excellent design. A drive unit(not shown) of the clock is disposed on a rear side of the transparentsubstrate 11 (positioning on a rear side of the Figure), and voltage isapplied to the terminals 15 and 16, whereby a composite layer providedin a region 63 e surrounded by the seal material 63 becomesnon-transparent.

By employing a mirror or a colored substrate instead of the transparentsubstrate 11, it is possible to produce a clock having an excellentdesign.

As shown in FIG. 10( a), a plurality of regions each surrounded by aseal material 73 may be provided in a region surrounded by the sealmaterial 14. By injecting a composite into the regions each surroundedby the seal material 73, a plurality of circular patterns arranged in amatrix form can be displayed. Further, by providing light-emitting diodechips 701 on a rear side of the transparent substrate 11 (positioning onrear side of the Figure) so as to correspond to the circular patterns,it is possible to realize light-emitting circular patterns. Namely, eachdiode chip is substantially a point light source, but by making thecomposite layer in the region 73 a a scattering state (FIG. 10( c)),light emitted from each light-emitting diode chip is scattered. As aresult, it is possible to illuminate entirety of each region 73 a. Eachlight-emitting diode 701 is connected to a power supply circuit 702through such as a transparent wiring 703 of ITO formed on rear surfaceof a transparent substrate 71, for instance. Here, the light-emittingdiode 701 may be embedded in a laminated glass, and the laminated glassmay be employed instead of the transparent substrate 11.

Finally, FIG. 11 shows a liquid crystal display device 80 having thesame configuration as that shown in FIG. 1 except that seal materials 83for forming composite layers are laid out to display characters of AGC.By this configuration, it is possible to display such as characterswithout patterning electrodes.

As described above, in the liquid crystal display device according tothe present invention, only a partial area in the transparent substrates11 and 12 requiring liquid crystal displaying needs to be filled withexpensive liquid crystal material. Graphics, symbols and characters canbe displayed without patterning ITO electrodes. The liquid crystal panelcan be produced with low cost.

Meanwhile, in the above description, a liquid crystal and cured productcomposite device is explained, but the present invention is not limitedthereto. The present invention can be applied to a normal liquid crystaldisplay device only having liquid crystal. In the same manner as thecase of liquid crystal and cured product composite device, it ispossible to provide a liquid crystal display device of lower cost thanbefore, which can perform a liquid crystal display only in a partialarea. Further, explanation has been made with respect to a passive typeliquid crystal display device, but besides this, the present inventioncan be applied to liquid crystal display devices of other drivingmethods such as those of static or active.

EXAMPLE

Next, an example of the present invention will be described.

On each of ITO electrodes as transparent electrodes made of ITO thinfilm (indium tin oxide) formed on opposed surfaces of a pair of glasssubstrates, a SiO₂—TiO₂ system metal oxide thin film (MIC-55manufactured by AGC SEIMI CHEMICAL CO., LTD.) was formed as aninsulating layer. Further, on the metal oxide thin film, an alignmentfilm being a polyimide thin film having a pretilt angle of about 90° wasformed. On one of the pair of glass substrates on which films are thusformed, spacers (Micropearl KH, 10.5 μm, manufactured by SEKISUICHEMICAL CO., LTD.) were sprayed, and they were subjected to a heattreatment at 110° C. for 10 minuets to be fixed onto the substrate.

Next, a UV curable adhesive agent (OP-2070, viscosity 700,000 mPa·s,refractive index 1.55, manufactured by Denki Kagaku Kogyo KabushikiKaisha) was applied by a dispenser along the outer periphery of thesubstrates while the adhesive agent was warmed up to 50° C. The adhesiveagent was further applied on the substrate surface to form a shape inwhich liquid crystal drive was desired. Next, inside the seal materialhaving a shape in which liquid crystal driving was desired, a compositeof liquid crystal having negative dielectric anisotropy and a curablecompound, was dropped in a predetermined amount calculated from the areaand a gap between the substrates.

Next, on other area, a UV-curable adhesive agent (No. 68, viscosity2,500 mPa·s, refractive index 1.56, manufactured by NORLAND PRODUCTSINC.) was dropped in a predetermined amount calculated from the area anda gap between the substrates in the same manner. The glass substrate onwhich the liquid crystal is dropped was laminated with another glasssubstrate to be opposed thereto in a vacuum laminating apparatus forproducing liquid crystal panel. Next, at a room temperature, bothsurfaces of the laminated substrates were irradiated with UV rays havinga central wavelength of 365 nm and an irradiation intensity of 30 W/m²for 10 minutes, to cure the curable compound to thereby obtain a liquidcrystal display device.

Entire panel of the liquid crystal display device obtained wastransparent at a time of non-voltage application, and only an areahaving a shape in which drive is desired was able to be changed tocloudy state of scattering by applying a voltage.

INDUSTRIAL APPLICABILITY

As described above, the present invention enables to have a displayfunction only in a partial area of the substrate, and provides a meritthat it requires only a little amount of liquid crystal material.Further, the present invention is suitably applicable to an automobilehaving a display function or a building window glass.

The entire disclosure of Japanese Patent Application No. 2006-305361filed on Nov. 10, 2006 including specification, claims, drawings andsummary is incorporated herein by reference in its entirety.

1-10. (canceled)
 11. A liquid crystal display device, comprising firstand second substrates that are disposed so as to oppose each other andeach having a transparent electrode; a first seal material for forming afirst space between the first and second substrates; a second sealmaterial for forming a second space between the first and secondsubstrates; a composite layer positioned in the first space andcontaining liquid crystal and a cured product; and a transparent resinlayer provided in the second space and containing no liquid crystal;wherein the composite layer and the first and second seal materials eachhas a visible light transmittance of at least 70% in a transparentstate; and the second space enclosed by the first and second substratesand the first and second seal materials is filled with the transparentresin layer without gap.
 12. The liquid crystal display device accordingto claim 11, wherein the seal material comprises a polyene-polythiolsystem polymer.
 13. The liquid crystal display device according to claim11, wherein an absolute value of the difference between a haze value ofthe first and second seal materials and a haze value of the compositelayer in a transparent state is at most 3%.
 14. The liquid crystaldisplay device according to claim 11, wherein the composite layer showsa scattering state at a time of voltage application and the compositelayer shows a transparent state at a time of no voltage application. 15.The liquid crystal display device according to claim 14, wherein thetransparent resin layer has a visible light transmittance of at least70%, and at a time of no voltage application, the composite layer showsa transparent state and the entire liquid crystal display device becomestransparent.